This invention relates to apertured webs for body exudates absorbent garments such as skin-contactable sheets for disposable diapers and sanitary napkins.
FIG. 8 of the accompanying drawings is a perspective view of a microapertured polymeric web 110 described in Japanese Patent Application Disclosure Gazette (Kokai) No. Sho62-57551 in which the web 110 exhibiting a substantially uniform soft and silky tactile impression. The web 110 is intended to be used as a topsheet or a backsheet in a disposable diaper and made from a relatively thin plastic material as a starting web. Specifically, the starting web is placed on a support such as a mesh wire and transported into a processing zone in which the starting web is subjected to high pressure liquid jets.
The apertured polymeric web 110 is formed on its skin-contactable surface with a plurality of cylindrical projections 120 which have, in turn, microapertures 125 at their tops. Each of these microapertures 125 is formed along its peripheral edge with irregularly shaped petals. The web 110 is claimed to have a soft fabric-like touch and to present no surface gloss.
Whether the polymeric web used in disposable diapers or sanitary napkins present a soft touch or not when such web is in contact with the wearer's skin is often determined on the basis of a certain softness reference, for example, softness of a woven or nonwoven fabric made of natural fibers or synthetic fibers.
In the polymeric web, a peripheral edge of each microaperture formed at the top of each cylindrical projection is finely divided so as to form the irregularly shaped petals. Probably the irregularly shaped petals provide a soft fabric touch when the wearer's skin rubs the irregularly shaped petals. However, even when the polymeric web is formed with a plurality of the cylindrical projections, there is an apprehension that these projections may rather increase a rigidity of the web. Accordingly, it is difficult for the polymeric web to reconcile a high softness and a high drapeability as provided by a woven--or nonwoven fabric. A topsheet in a body exudates absorbent garment can comfortably adopt itself to the wearer's skin only when the softness and drapeability are well reconciled.
A drapeability of the polymeric web can be improved by thinning the polymeric web. For example, use of low density polyethylene having a thickness of 0.001.about.0.020 mm as the topsheet in disposable diapers or sanitary napkins will be effective to improve the drapeability. However, such excessively thin web will inevitably confront problems such that the web must be handled with excessive carefulness during the process for manufacturing diapers or napkins and the web can not be easily peeled off from the wearer's skin once the web has been electrostatically attracted on the wearer's skin.